A technique has been known which generates an overhead image being a view looked down from a virtual viewpoint above by projecting a camera image onto the ground. In the overhead image generated in this way, an object positioned at the height of the ground is normally displayed. On the other hand, an object having three-dimensional shape is displayed in a greatly distorted form in which the object is extended as if it falls down onto the ground.
Regarding this problem, for example, in Patent Document 1, the following technique is disclosed: in a camera image taken with a camera that shoots a direction in which an obstacle is detected, the width of the image positioned in a region farther than the obstacle viewed from a vehicle is compressed toward the center of a vehicle surrounding image (overhead image), thereby generating the vehicle surrounding image. This technique prevents the three-dimensional obstacle from being displayed distortedly in the overhead image. In this technique, the obstacle is detected with a sensor like an ultrasonic sensor.